Bacterial classification, strucutre, nutrition and growth Flashcards
What is the smallest infectious particle called?
virus
How big are viruses?
18-600 nanometers
What do viruses need to replicate?
a host cell (i.e it is a true parasite)
Are bacteria prokaryotic or eukaryotic
prokaryotic
How big are bacteria?
1-20 micrometers
How many cells do bacteria have?
one they are unicellular
Do bacteria have a nuclear membrane?
no, in fact they have no membrane bound organelles
How do bacteria reproduce?
via asexual division
Are fungi eukaryotic or prokaryotic?
eukaryotic
Do fungi have membrane bound organelles?
yes
What do the membranes of fungi have in them?
a unique sterol called ergosterol?
what is the sterol found in the membrane of fungi?
ergosterol
How do fungi undergo replication?
Unicellular fungi like yeast undergo asexual rep.
Filamentous (like mold) can replicated sexually or asexually?
What type of fungus can replicate asexually?
both filamentous and unicellular
What type of fungus can replicate sexually?
filamentous
Are parasites eukaryotic or prokaryotic?
eukaryotic
How big are parasites?
1-2 micrometers (protozoa) to 10 meters (tapeworms)
What is the most complex microbe?
parasites
Are parasites unicellular or multicellular?
they are both :)
What is a great therapeutic drug target on fungi?
there sterol called ergoterole
What are the 7 ways you can classify a bacteria?
shape arrangement cell wall structure antigenic (i.e absence or presence of specific antigens) Metabolism Ability to lyse erythrocytes Fermentation of sugars
What are the three shapes a bacteria can be in?
spherical-coccous
Rod-Bacillus
spiral-spirillum
What are the 2 arrangments bacteria can be in?
chains- single division plane
clumps- multiple division plane
What are the three different cell wall strucutures a bacteria can have?
Gram positive
Gram negative
Acid fast (wax like nearly impermeable cell walls)
What is the least effective way of classifying bacteria?
arrangements
What is the most important way to identify bacteria?
cell wall structure
What can an acid fast stain tell you?
if you have TB
Staph forms clumps or chains?
clumps
Strep forms clumps or chains?
chains
What are the three ways you can classify bacteria based upon metabolism?
aerobic
facultative anerobe
anearobic
(Blank) can grow with or without oxygen because they can metabolise energy aerobically or anaerobically. They gather mostly at the top because aerobic respiration generates more ATP than either fermentation or anaerobic respiration
Facultative anaerobe
What are the 2 ways to classify a bacterials ability to lyse erythrocytes?
hemolytic and nonhemolytic
How do you classify a bacterias abilty to ferment sugars?
fermenter
non-fermenter
What are the four group habits that you use to classify microbial pathogens?
extracellular
intracellular
toxin producer
pyogenic cocci
What are 2 main characteristics of extracellular microbial pathogens?
they cannot survive inside the phagocyte
they are often controlled by phagocytes
What are the 2 main characteristics of intracellular microbial pathogens?
grows inside phagocytes
often controlled by T cell based immunity
How do you know if a microbial pathogen is a toxin producer?
symptoms will appear at distant sites
How do you know if a microbial pathogen is a pyogenic cocci?
pus will form
What can the system affected and measns of acquisition (i.e foodborne, zoonotic, etc) tell you?
tell you what microbial pathogen you are dealing with
T or F
Intracellular bacteria can live inside a resting macrophage?
T
What are some differences in structure between bacteria and humans?
cell wall cytoplasm nucleic acid synthesis protein synthesis metabolic pathways
What is the importance of the differing structures between humans and bacteria?
the structures that only the bacteria have can be targeted for therapeutics.
Bacterial structures contribute to (blank). How?
pathogenesis
inflammation, resistance to host factors, adherence to cells and tissues
Explain the structure of a bacterial chromosome
its a single double-stranded cirlce with no nucleus or nuclear membrane
What is a plasmid? What does it do?
small, extra chrmosomal DNA
may encode extra, non-essential functions (i.e toxins, or antibiotic resistance)
Describe the structure of a bacterial ribosome
30S + 50S-> 70s
Are bacterial proteins similiar to eukaryotic proteins?
NOOO they are very different
Does the cytoplasmic membrane of a bacteria have sterols?
no EXCEPT for mycoplasma, that has cholesterol in it that it steals from humans
What is the basic structure of the cell wall of all bacteria made by?
peptidoglycan
What is the sugar backbone of peptidoglycan made up of?
N actetyl glucosamine and N-acetylmuramic acid in a repeating dissacharide unit
THere are four peptides attached to the (blank) of the sugar backbone of peptidoglycan. What do you call the four peptides?
N-acetylmuramic acid
a stem peptide
How do you link a stem peptide to a fellow stem peptide of another repeating disaccharide backbone?
via a glycine transpeptidization cross bridge.
How do you synthesize peptidoglycan?
in the cytoplasma you create a water soluble precursor that attaches to the insides of the cytoplasmic membrane and then flips to the outside of this membrane where it will cross link 3 dimensionally
What do you call the step in peptidogycan biosynthesis where you have formation of linear polymers outside the membrane?
trans glycosylation
What do you call the step in peptidoglycan biosynthesis where you have cross-linking of polymers into a three-dimentional matrix?
transpeptidization
Explain Peptidoglycan synthesis in detail?
you have UDP muramic acid and add a pentapeptide and attach that sugar to a lipid on the inside of the cytoplasmic membrane. This will flip to the outside and you will add the second sugar which is GlcNAc then crosslinking wil occur via transpeptidization
What does vancomycin and beta lactam do?
inhibits transpeptidization so you wont get crosslinking and thus it fucks up the peptidoglycan and the bacterial cell wall
How do you stain bacteria to determine if it is gram positive or gram negative?
You fix the bacteria to the slide via heat or alcohol. Then you pour crystal violet onto the cells to stain all bacteria cell walls blue. Then you use grma iodine to trap the blue dye into gram positive cell walls.
Then you use decoloroizer to remove the crystal violet from gram negative cell walls. Then you had Safranin to stain the gram negative red
What color is gram negative bacteria?
red
What color is gram positive bacteria?
blue
a gram positive reaction relies on the integrity of the (blank)
cell wall
T or F
a gram positive bacterium can stain gram negative
T